There were 15 times more measles cases in Europe last year than in 2016, and new outbreaks were also recorded in South America and parts of Asia. Authorities in the Philippines said this week that a recent outbreak of the virus — with more than 1,800 cases so far — could put millions of children at risk. Measles immunization rates in the East Asian country have fallen to 60 percent, down 15 percent from the previous year, in part due to fearmongering over vaccines in a country that already struggles to inoculate its poorest.

In Washington State, the immunization rate is still at 90 percent, but researchers say that a rate of at least 95 percent is needed to prevent an outbreak.

“The picture for 2018 makes it clear that the current pace of progress in raising immunization rates will be insufficient to stop measles circulation,” Zsuzsanna Jakab, a Europe-focused senior official with the World Health Organization, was quoted as saying.